So, its very simple thing, but just cant figure it out ... You know, there is buttons and other gui elements, and in many programs, when you move your mouse over any button or icon or other element, then text box appears with that elements description, like you move mouse over new tab button in your internet browser, and text box appears with text "new tab". How to do this in java, i.e., for javax.swing.JButton, or any other element ?